High gloss polishable coatings with matt and/or structured metallic effect and method for their preparation

Abstract

Disclosed herein is a method for producing a multi-layer coating on a substrate including the steps of (i) forming a primer coat layer (P) on a substrate, (ii) forming a silver metal layer (S) onto the surface of the coating layer (P); and (iii) forming one or more clear top coat layers (T) onto the surface of the silver metal layer (S), where the primer coat layer contains one or more particulate components selected from the group consisting of matting agents and structuring agents and where the silver metal layer (S) is formed by reductive deposition from an aqueous alkaline ammoniac solution containing a soluble silver salt, by use of a reducing agent. Further disclosed herein are multi-layer coated substrates obtainable according to the above method.

1 . A method for producing a multi-layer coating on a substrate comprising the steps of
 (i) forming a primer coat layer (P) on a substrate,   (ii) forming a silver metal layer (S) onto the surface of the coating layer (P); and   (iii) forming one or more clear top coat layers (T) onto the surface of the silver metal layer (S), characterized in that   the primer coat layer contains one or more particulate components selected from the group consisting of matting agents and structuring agents and   wherein the silver metal layer (S) is formed by reductive deposition from an aqueous alkaline ammoniac solution containing a soluble silver salt, by use of a reducing agent.   
     
     
         2 . The method according to  claim 1 , wherein the substrate is a pre-treated or non-treated, pre-coated or non-precoated substrate selected from the group consisting of metals, polymers, wood, glass, mineral-based materials and composites of any of the afore-mentioned materials. 
     
     
         3 . The method according to  claim 1 , wherein the primer coat layer (P) is formed from a primer composition, the primer composition being selected from the group consisting of solvent-borne coating compositions and water-borne coating compositions; and being a one-pack compositions or a two-pack composition. 
     
     
         4 . The method according to  claim 3 , wherein the primer coat composition is a solvent-borne, two-pack coating composition. 
     
     
         5 . The method according to  claim 4 , wherein the solvent-borne, two-pack coating composition is an epoxy composition or a polyol-isocyanate composition. 
     
     
         6 . The method according to  claim 1 , wherein the primer coat layer (P) is a clear coat layer. 
     
     
         7 . The method according to  claim 1 , wherein the matting agent is selected from the group consisting of amorphous silica, precipitated silica, pyrogenic silica, silica gels, layered silicates, diatomaceous earth, the stearates of Al, Zn, Ca or Mg, waxy compounds, carboxylic acid-based waxes and urea-formaldehyde condensates. 
     
     
         8 . The method according to  claim 1 , wherein the matting agents have a volume median particle size (D 50 ) determined by laser diffraction from 2 to less than 20 μm. 
     
     
         9 . The method according  claim 1 , wherein the structuring agents are selected from the group consisting of inorganic materials, polyalkylenes and polyamides. 
     
     
         10 . The method according to  claim 1 , wherein the structuring agents have a volume median particle size (D 50 ) determined by laser diffraction from 20 to 150 μm. 
     
     
         11 . The method according to  claim 1 , wherein the layer thickness of the silver layer is in the range from 0.5 to 2.5 μm determined coluometrical. 
     
     
         12 . The method according to  claim 1 , wherein the clear top coat layer (P) is formed from a clear coat composition, the clear coat composition being selected from the group consisting of solvent-borne coating compositions and/or being a polyol-isocyanate two-pack composition. 
     
     
         13 . A multi-layer coated substrate, obtainable according to the method of  claim 1 , comprising:
 (a) a substrate;   (b) a primer coat layer (P) on top of the substrate,   (c) a silver metal layer (S) on top of the surface of the coating layer (P); and   (d) one or more clear top coat layers (T) on top of the surface of the silver metal layer (S); characterized in that the primer coat layer (P) contains one or more particulate components selected from the group consisting of matting agents and structuring agents.   
     
     
         14 . The multi-layer coated substrate according to  claim 13 , wherein the layer thickness of the dried and/or at least partially cured primer coat layer is in the range from 10 to 150 μm determined according to DIN EN ISO 2178; the layer thickness of the silver metal layer (S) is in the range from 0.5 to 2.5 μm determined coluometrical; and the layer thickness of the cured clear top coat layer is in the range from 20 to 200 μm determined according to DIN EN ISO 2178. 
     
     
         15 . The multi-layer coated substrate according to  claim 13 , wherein the volume median particle size (D 50 ) determined by laser diffraction for the matting agent is from 2 to less than 20 μm and for the structuring agent is 30 to 200 μm. 
     
     
         16 . The multi-layer coated substrate according to  claim 13 , wherein the primer coat layer (P) is a clear coat layer.